Window shelf



FIG. 1 is a top, front, and right side perspective view of a window shelf showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a reduced top plan view thereof;

FIG. 5 is a reduced bottom plan view thereof; and

FIG. 6 is a right side elevational view thereof, the left side being a mirror image of that shown. 

The ornamental design for a window shelf, as shown and described. 